Receiving system



Nov. 4, 1941. BABIK 2,261,327

RECEIVING SYSTEM Filed Jan. 5, 1959 INVENTOR wow/c; B/K

BY M

ATTORNEY Patented Nov. 4 194i RECEIVING SYSTEM Germany ApplicationJanuary 5, 1939, Serial No. 249,353 In Germany January 8, 1938 2 Claims.

It is already known in a receiver for high frequency transmission acrosswire to connect the antenna terminal of the receiver through a shieldedconnection cable with the locally fixed connection terminal for thepotential transmitted with high frequency across wire.

In accordance with the present novel feature this connection cable isdimensioned as regards thickness, length and its dielectric, in suchmanner that its parallel capacity between the inner conductor and theenvelope to be connected to the ground terminal of the receiver isapproximately equal to the normal antenna capacity for which thereceiver is designed (for instance, about 150-250 mmf.).

The advantage of the invention resides in that a receiver designed forordinary radio reception can also be connected for high frequency wiretransmission while obtaining the highest possible efficiency.

An example embodying the novel feature is shown in the accompanyingdrawing.

The potential transmitted through high frequency transmission by wirelies at the upper terminal K1 of the socket D. The lower terminal K2 isgrounded. In order to connect the terminals K1 and K2 with the antennasocket A and the ground bushing E of the receiver P the cable K is usedwhich consists of the metallic envelope M, the inner conductor J and thedielectric L. The inner conductor is brought out from the cable at theend facing the socket D and then connected with a plug S1 inserted intothe socket bushing K1. The corresponding end of the envelope M has awire soldered thereto which is connected with the plug S2. When the plugS2 is inserted into the grounded bushing K2 the cable envelope isthereby grounded. At the otherend of the cable the inner conductor isconnected to the antenna bushing A across the plug S3, and the envelopeis connected with the ground bushing E across the plug S4. As regardsthe length and thickness of the cable as well as its dielectric thedimensions are such that the capacity between the interior conductor andthe outer envelope is 200 mmf. The input circuit of the receiver P islikewise designed for the same capacity which in general is assumed asthe mean antenna capacity.

The inner conductor is interrupted at the end facing the connectionsocket, by means of a block condenser of about -50 mmi. placed in thecable and designated by C. This block condenser serves for attaining aloose coupling of the receiver with the voltage source existing betweenthe terminals K1 and K2. The cable part from the wire signal transmitterup to the connection socket D is in general terminated. by an ohmicresistance at the end facing the socket which resistance is ohms andwhich in case of a close coupling with the input circuit of the receiverwould cause a high damping of v the latter. The condenser C preventsthis damping.

I claim:

1. In an arrangement for connecting the antenna and ground terminals ofa radio receiver which is designed for operation with an antenna systemhaving a predetermined normal capacity, to a transmission line which isadapted to have impressed upon it signals desired to be received, ashielded cable comprising an inner conductor, a condenser connected tosaid inner conductor and a metallic shield insulated from andsurrounding the condenser and the inner conductor, means for connectingthe inner conductor between one of the receiver terminals and one of theconductors of the transmission line, and means for connecting themetallic shield of said cable between the other receiver terminal andanother conductor of the transmission line, said cable being arranged tohave a capacity between its inner conductor and the shield which isapproximately equal to said predetermined normal capacity.

2. In an arrangement for connecting the antenna and ground terminals ofa radio receiver to a transmission line adapted to have impressed uponit signals desired to be received, said radio receiver being designedfor operation with an antenna system having a predetermined normalcapacity, a shielded cable having an inner conductor, a condenserconnected to said inner conductor and a metallic shield insulated fromand surrounding the condenser and the inner conductor, means connectingthe inner conductor between the antenna terminal of the receiver and oneof the conductors of the transmisison line, and means connecting themetallic shield of said cable between the ground terminal of thereceiver and the other conductor of the transmission line, said cablebeing arranged to have a capacity between its inner conductor and theshield thereof which is of the order of said predetermined normalcapacity.

LUDWIG BABIK.

